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WO1993021351A1 - Aciers depourvus d'elements interstitiels - Google Patents

Aciers depourvus d'elements interstitiels Download PDF

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Publication number
WO1993021351A1
WO1993021351A1 PCT/CA1992/000155 CA9200155W WO9321351A1 WO 1993021351 A1 WO1993021351 A1 WO 1993021351A1 CA 9200155 W CA9200155 W CA 9200155W WO 9321351 A1 WO9321351 A1 WO 9321351A1
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WO
WIPO (PCT)
Prior art keywords
steel
rolling
ferrite
grain size
roughing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/CA1992/000155
Other languages
English (en)
Inventor
John Joseph Jonas
Stephen Yue
Abbas Najafi-Zadeh
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
McGill University
Original Assignee
McGill University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by McGill University filed Critical McGill University
Priority to AU16400/92A priority Critical patent/AU1640092A/en
Publication of WO1993021351A1 publication Critical patent/WO1993021351A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0231—Warm rolling
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B2201/00—Special rolling modes
    • B21B2201/04—Ferritic rolling
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/005—Ferrite
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0226—Hot rolling

Definitions

  • This invention relates to a method of processing an interstitial free steel to increase strength and toughness of the steel; and to an inter ⁇ stitial free steel having an average grain size of up to 5 ⁇ m, in particular ultra-fine grain sizes of 1 to 2 - m, in particular such steels exhibit superior strength and toughness.
  • interstitial elements i.e, C and N
  • concentration of interstitial elements i.e, C and N
  • removal of these elements from the matrix is performed largely by vacuum degassing techniques.
  • the resulting low interstitial concentration can be further reduced by the addition of Ti and/or Nb or Zr, which combine with C and N, leading to a solute level of these elements of only a few parts per million.
  • These steels are known as interstitial free, or IF steels, and are, at present, mainly used in deep drawing applications.
  • a method of processing an interstitial free steel to increase strength and toughness of the steel comprising warm finish rolling an interstitial free steel in the single phase ferrite region below -A , to effect ferrite dynamic recrystal ⁇ lization of the steel microstructure to a ferrite structure of an average grain size of at most 5 ⁇ m.
  • an interstitial free steel of increased strength and toughness produced by warm rolling an interstitial free steel at a temperature below A , in the single phase ferrite region to effect ferrite dynamic recrystallization of the steel micro ⁇ structure to a ferrite structure of an average grain size of at most 5 ⁇ m, more especially an ultrafine grain size of less than 2 ⁇ m.
  • an interstitial free steel of superior strength and toughness characterized by a ferrite structure of at most fine grain size.
  • the method of the invention particularly contemplates subjecting the steel to a rolling schedule comprising a plurality of roughing rolling processes followed by a plurality of finishing rolling passes.
  • the roughing rolling passes are carried out in the single phase austenite region above A _ and the finishing rolling passes are carried out in the single phase ferrite region below A , .
  • both the roughing rolling passes and the finishing rolling passes are carried out in the single phase ferrite region below A , .
  • interstitial free steels are to be understood as steels having a carbon content in wt. % of less than 0.01%, preferably less than 0.008%, and most prefer ⁇ ably about 0.0035%, and a nitrogen content in wt. % of less than 0.01%, preferably less than 0.008%, and most preferably about 0.0035%.
  • an ultrafine grain size means average grain sizes of about 1 to 2 ⁇ m; and fine grain size means average grain sizes of about 3 to 5 ⁇ m.
  • the grain size of at most 5 ⁇ m in IF steels results in an increase in strength of 25 to 100%; and the ductile to brittle transition temperature is decreased by up to 100°C, as compared with conventional steels which have a grain size of more than 10 ⁇ m.
  • the interstitial free steels will typically have a content of at least one element selected from titanium, niobium and zirconium, to a total of 0.01 to 0.15%, usually 0.01 to 0.1% by weight.
  • the inclusion of at least one of these elements, although in a small amount, serves to remove C and N from solution in the steel, by combining with the C and N to leave the ferrite structure as an essentially interstitial free structure.
  • FIG. 1 illustrates the effect of the grain size of ferrite on the yield strength, and the toughness or impact transition temperature
  • FIG. 2 demonstrates the dependence of the mean flow stress on the inverse absolute temperature for interstitial free steels (IF) and high strength low alloy steels (HSLA) ;
  • FIG. 3 illustrates diagrammatically the time/temperature schedules for the first and second methods in accordance with the invention;
  • FIG. 4 is a plot of stress-strain curves for IF steel A processed in accordance with the first method of the invention employing a temperature of 710 C. for the first finishing rolling pass;
  • FIG. 5a is a microphotograph showing the ultrafine ferrite structure of the IF steel A of FIG. 4;
  • FIG. 5b is a microphotograph similar to FIG. 5a showing the further reduction in grain size for steel of the same composition as IF steel A achieved by a lowering of the temperature of the first finish ⁇ ing rolling pass to 590 C;
  • FIG. 6 is a plot showing the dependence of ferrite grain size of IF steels A, B and C, on the inverse absolute temperature of the first finishing rolling pass in the first method of the invention
  • FIG. 7a is a plot of stress-strain curves for an IF steel B processed in accordance with the second method of the invention
  • FIG. 7b is a plot of stress-strain curves for an IF steel C processed in accordance with the second method of the invention
  • FIG. 8 is a plot of mean flow stress against inverse absolute temperature for IF steels A, B and C processed in accordance with the second method of the invention.
  • FIG. 9 is a plot corresponding to FIG. 8 for IF steels A, B and C processed under conventional rolling conditions, for comparison purposes with FIG. 8;
  • FIG. " 10 is a microphotograph showing the ultrafine ferrite grain size of IF steel B processed by the second method of the invention
  • FIGS. 11a, lib and lie are microphotographs showing the ferrite grain size of IF steel A processed under dif erent conventional rolling conditions
  • FIG. 12 is a plot showing the dependence of ferrite grain size of IF steels A, B and C on the inverse absolute temperature of the first finishing pass when processed under conventional rolling con ⁇ ditions.
  • a strip rolling schedule comprising a plurality of roughing rolling passes followed by a plurality of finishing rolling passes.
  • the rollings are carried out at elevated temperatures but the steel is allowed to cool during the successive rollings suc ⁇ that the rollings are carried out at successively lower temperatures.
  • the rolling temperatures decrease with successive rollings from a first roughing rolling pass to a final roughing rolling pass and then from a first finishing rolling pass to a final finishing rolling pass.
  • the rolling temperature of the first finishing rolling pass is lower than the rolling temperature of the final roughing rolling pass.
  • the rollings are carried out to achieve ferrite dynamic recrystallization of the steel micro ⁇ structure and- this requires appropriate control of the temperature of rolling, the interpass time between successive rollings, but also is dependent on the interstitial content of carbon and nitrogen in the steel. It is found for interpass times typical in conventional strip rolling that dynamic recrystal ⁇ lization of ferrite in IF steels occurs by rolling at temperatures well below the A , to eliminate con- ventional static recrystallization in the interpass intervals, and in this way permitting the accumulation of strain that leads to the initiation of dynamic recrystallization.
  • Ferrite dynamic recrystallization occurs when the steel is subjected to load as in a rolling pass. During application of the load during a rolling pass the crystals are plastically deformed to a more flattened form, and then recrystallize with small grain size while still under load; in this way the ferrite dynamic recrystallization occurs while the steel is under load during rolling.
  • At least the finishing rolling passes are warm rolling passes in the single phase ferrite region of the steel or in other words are carried out below A , , the temperature below which the transformation of the austenite microstructure of the steel to the ferrite micro ⁇ structure has been completed.
  • the roughing rolling passes are carried out in the single phase austenite region well above A _ , the temperature
  • the roughing rolling passes are suitably carried out at a temperature in the range of 1280°C. to 1050°C, preferably 1250°C. to 1100°C.
  • the finishing rolling passes are suitably carried out at a temperature in the range of A , to 275 below A ., preferably 750 P C to 600°C. and more preferably 700°C. to 650°C. , with a delay time between successive passes of 3.5 to 0.5 or less seconds.
  • the temperature of the finishing rolling passes should be at least 150 C below A - . In particular it is pre- ferred that the final finishing passes be at delay times of less than 2 seconds.
  • the roughing rolling passes are suitably carried out at a temperature in the range of A . to 50 C. below A , .
  • the finishing rolling passes are suitably carried out at a temperature in the range of A , to 275 below A , , preferably 750°C. to 600°C. and more preferably 700°C. to 650 C. with a delay time between successive passes of 3.5 to 0.5 or less seconds, and it is preferred that the final finishing passes be at delay times of less than 2 seconds. It is especially preferred that the finishing rolling passes be at temperatures below the roughing rolling passes.
  • At least the finishing rolling passes are warm rolling passes in the single phase ferrite region of the IF steels, or in other words are carried out below A , , the temperature below which the transformation of aus ⁇ tenite to ferrite microstructure of the steel on cooling is completed.
  • both the roughing and finishing rolling passes are warm rolling passes carried out in the single phase ferrite region below A , of the IF steel.
  • finish rolling passes are normally carried out with different rolls which are usually harder because the finish rolling passes are carried out at lower temperatures at which the resistance to working is greater.
  • the accumulated strain in finish rolling is greater than 1.5, so that dynamic recrystallization is both initiated and propogated.
  • FIG. 1 of the drawings is a plot taken from F. B. Pickering, Physical Metallurgy and Design of Steels, p. 16, Applied Science Publishing Ltd., 1978, U.K. which shows the effect of ferrite grain size on yield stress and toughness (impact transition temperature) in steel, and Table 1 below demonstrates the effect which reduction of ferrite grain size has on the yield strength and impact transition temperature of IF steels. Table 1. Estimated effect of reducing the ferrite grain size on the yield strength and impact transition temperature of IF steels
  • Table 1 demonstrates that ultrafine ferrite microstructure leads to an increase in strength of up to 100% as compared with fine grain ferrite structures.
  • the present invention and the conventional method of hot rolling steel are differentiated in FIG. 2, which illustrates the dependence of the mean flow stress, i.e., the resistance to hot deformation, on the inverse absolute temperature for IF and con- ventional HSLA steels.
  • This diagram can be used to distinguish between three deformation processing regions (the regions corresponding to the IF and conventional HSLA steels, respectively are shown in the lower and upper parts of this diagram) .
  • REGION I is a single phase austenite region where hot rolling conventionally takes place. For this type of processing, all rolling passes are executed at temperatures above A r v the temperature below which the transformation of austenite-to-ferrite begins.
  • REGION II corresponds to rolling in the inter ⁇ critical region, a two phase region of austenite and ferrite. Such processing is not used in IF steels because the temperature range is too narrow and the rate of mean flow stress change is rapid, both effects leading to process control difficulties.
  • the dif ⁇ ference between the A -. and A (the temperature below which the microstructure has completely transformed to ferrite) is considerably greater in steels of con- ventional interstitial levels and thus rolling in REGION II can be used in such conventional steels.
  • REGION III is rolling at elevated temperatures in the single phase ferrite region, and is usually referred to as warm rolling. In conventional steels, decreasing the temperature into REGION III increases the mean flow stress rapidly and hence the rolling load.
  • IF steels can be processed extensively in this region, in which there are appreciably lower flow stresses displayed by the IF steels .
  • the mean low stresses typical of IF and HSLA 'steels are compared in FIG. 2.
  • Method 1 In an industrial scenario, in order to accommodate the higher roughing temperature of the first method of the invention (Method 1) a longer delay time between roughing and finishing is necessary. This longer delay time allows the temperature of the steel to decrease below the A , to enable finish rolling to be performed in the single phase ferrite region.
  • H. height (thickness) before rolling pass
  • H . height (thickness) after rolling pass.
  • Other formulas apply for other processes, for example, rod rolling.
  • the roughing rolling passes (Rl to R7 in Table 3 ) are carried out in the austenitic region with the first roughing rolling pass (Rl in Table 3) at 1260°C; and the first finishing rolling pass (Fl in Table 3) at 710 C, which is significantly below the A , of about 850 C. of these steels.
  • the roughing rolling passes (Rl to R7 in Table 3) are carried out in the ferrite region with the first roughing rolling pass (Rl in Table 3) at 850°C, i.e., below the A , of about 860 C, and the first finishing rolling pass (Fl in Table 3) at 700°C.
  • the delay time between the final roughing rolling pass (R7 in Table 3) and the first finishing rolling pass (Fl in Table 3) is 300 seconds and is twice the corresponding delay time of 150 second in Method 2.
  • FIG. 4 illustrates the flow curves associated with the simulated finishing passes (Fl to F5 in Table 3) for an IF steel A of Table 2 containing 0.06% Ti, rolled according to the first strip rolling schedule of Table 3.
  • strain i.e., work hardening
  • FIG. 5a The microstructure corresponding to the rolling schedule of FIG. 4 is shown in FIG. 5a. It is apparent that dynamic recrystallization of the ferrite produced a rather fine ferrite grain size of 1.8 ⁇ m when the first finishing pass temperature T ⁇ r 1, , was
  • FIGS. 7a and 7b show the flow curves for the two IF steels rolled totally in the ferrite region, where the temperatures of the first roughing and finishing passes are 850 and 700°C, respectively.
  • FIG. 8 illustrates the mean flow stress vs. inverse absolute temperature curves corresponding to the flow curves of FIG. 7. It can be seen that the maximum mean flow stress encountered in roughing is 115 MPa. For comparison, the behaviour of the IF steels under conventional rolling conditions is presented in FIG. 9.
  • the temperatures of the first roughing and finishing passes are 1260 and 960°C, respectively, corresponding to hot rolling entirely above the A ... From FIGS. 8 and 9, it can be seen that the maximum mean flow stress achieved in roughing using Method 2 is only approximately 30 MPa greater than that of the conventional - schedule. Furthermore, the difference between the maximum mean flow stress levels of the respective finishing schedules is less than 20 MPa.
  • the mean flow stresses calculated for each pass strain and temperature must be corrected for the actual strain rates experienced in the finishing mill using an equation of the form:
  • k Is the strength coefficient, which depends on the pass strain, temperature and material, and m is the strain rate sensitivity ( ⁇ 0.08 for IF steels in the finishing passes).
  • the mean flow stress, o"_, at a mill strain rate of ⁇ . can be calcu- lated from the simulation stress, l , and strain rate. g, from the equation:
  • microstructure correspond- ing to Method 2 is shown in FIG. 10, and reveals an ultrafine ferrite grain size of 1.9 ⁇ m.
  • results of the present invention can be put into perspective by comparing the microstructures produced by the method of the invention (FIGS. 5, 6 and 10) with the grain sizes produced by the con ⁇ ventional rolling process for the IF steel A, i.e., deformation in the austenite region, (FIGS. 11 and 12).
  • any ultrafine grain size structure can be destroyed by grain growth.
  • the sensitivity to grain growth is minimized by finishing at low temperatures.
  • the present invention can be applied to various hot working methods, including strip and rod mills, seamless tube mills, planetary hot rolling and extrusion.
  • the content of the at least one element selected from Ti, Nb and Zr is suitably a total of 0.01 to 0.15%, by weight of the steel.
  • the total content of the at least one element will be about 0.04 to 0.07%, by weight.
  • amounts of the at least one element In excess of 0.15%, by weight may be employed without departing from the spirit of the invention. Higher amounts have the disadvantage that they involve higher costs; additionally higher amounts result in hardening of the steel and this has the disadvantage that the steel becomes less workable.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Heat Treatment Of Steel (AREA)

Abstract

La robustesse d'aciers dépourvus d'éléments interstitiels est augmentée de l'ordre de 100 %, et la température de transition de résilience est diminuée de l'ordre de 100 °C par finissage à chaud au laminoir dans la région ferritique à phase unique au-dessous de Arl, afin d'effectuer la recristallisation dynamique de ferrite de la microstructure de l'acier en une structure de ferrite présentant une grosseur de grain atteignant 5 νm, et en particulier une grosseur de grain ultrafine de 1 à 2 νm; le procédé peut être utilisé au cours de différents procédés d'usinage à chaud, y compris dans les laminoirs à bandes et à fils, et pour le laminage planétaire à chaud et l'extrusion.
PCT/CA1992/000155 1991-02-08 1992-04-10 Aciers depourvus d'elements interstitiels Ceased WO1993021351A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU16400/92A AU1640092A (en) 1992-04-10 1992-04-10 Interstitial free steels

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US07/652,872 US5200005A (en) 1991-02-08 1991-02-08 Interstitial free steels and method thereof

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WO1993021351A1 true WO1993021351A1 (fr) 1993-10-28

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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997026377A1 (fr) * 1996-01-14 1997-07-24 Thyssen Stahl Ag Procede de laminage a chaud de feuillards d'acier
WO1998001589A1 (fr) * 1996-07-08 1998-01-15 Mannesmann Ag Procede de fabrication de tuyaux d'acier sans soudure
WO2000046411A1 (fr) * 1999-02-05 2000-08-10 Centre De Recherches Metallurgiques Asbl Procede de fabrication d'une bande d'acier laminee a chaud pour emboutissage
WO2006118425A1 (fr) * 2005-05-03 2006-11-09 Posco Feuille d’acier laminee a froid ayant une formabilite superieure et un rapport de rendement eleve et son procede de production
WO2006118423A1 (fr) * 2005-05-03 2006-11-09 Posco Feuille d’acier laminee a froid ayant une formabilite superieure et son procede de production
WO2006118424A1 (fr) * 2005-05-03 2006-11-09 Posco Feuille d’acier laminee a froid ayant un rapport de rendement eleve et moins d’anisotropie et son procede de production
WO2008006346A3 (fr) * 2006-07-12 2008-06-26 Univ Kassel Procédé de fabrication d'un demi-produit en tôle adapté pour le formage à chaud
CN101184858B (zh) * 2005-05-03 2010-12-08 Posco公司 具有优良的可成形性的冷轧钢板及其制造方法

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* Cited by examiner, † Cited by third party
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EP0585843A3 (en) * 1992-08-28 1996-06-26 Toyota Motor Co Ltd High-formability steel plate with a great potential for strength enhancement by high-density energy treatment
US6027587A (en) * 1993-06-29 2000-02-22 The Broken Hill Proprietary Company Limited Strain-induced transformation to ultrafine microstructure in steel
DE19628714C1 (de) * 1996-07-08 1997-12-04 Mannesmann Ag Verfahren zur Herstellung von Präzisionsstahlrohren
CN1088117C (zh) * 1997-04-30 2002-07-24 川崎制铁株式会社 高延展性且高强度的钢材及其制造方法
BR9806104A (pt) * 1997-06-26 1999-08-31 Kawasaki Steel Co Tubo de aço de granulação superfina e processo para a produção do mesmo.
ATE312208T1 (de) * 1997-06-26 2005-12-15 Jfe Steel Corp Verfahren zur herstellung von stahlrohr mit ultrafeinem gefüge
EP0945522B1 (fr) * 1997-09-11 2005-04-13 JFE Steel Corporation Procede de fabrication de toles d'acier laminees a chaud et ayant des grains hyperfines
FR2783444B1 (fr) * 1998-09-21 2000-12-15 Kvaerner Metals Clecim Procede de laminage d'un produit metallique
TW477822B (en) * 1999-02-26 2002-03-01 Nat Res Inst Metals Manufacturing method for steel with ultra fine texture
EP1559804A4 (fr) * 2002-10-17 2006-01-25 Nat Inst For Materials Science Produit forme et procede de production associe
KR102426248B1 (ko) * 2020-11-05 2022-07-28 주식회사 포스코 선영성이 우수한 고강도 아연계 도금강판 및 그 제조방법
CN116288035A (zh) * 2023-02-09 2023-06-23 包头钢铁（集团）有限责任公司 一种特深冲级Nb-IF冷轧钢板

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2362658A1 (de) * 1972-12-23 1974-07-18 Nippon Steel Corp Stahlblech mit hervorragender pressverformbarkeit und verfahren zu dessen herstellung
FR2524493A1 (fr) * 1982-04-03 1983-10-07 Nippon Steel Corp Acier ferritique a grains ultra-fins et son procede de production
EP0098564A1 (fr) * 1982-07-09 1984-01-18 MANNESMANN Aktiengesellschaft Procédé de fabrication de tôles soudables à grain fin pour grands tubes
EP0120976A1 (fr) * 1982-10-08 1984-10-10 Kawasaki Steel Corporation Procede de fabrication d'acier lamine a froid pour l'emboutissage profond
EP0196788A2 (fr) * 1985-03-06 1986-10-08 Kawasaki Steel Corporation Procédé de fabrication de tôles d'acier minces laminées, aptes à la mise en forme
BE905966A (fr) * 1986-07-10 1987-06-17 Centre Rech Metallurgique Aciers pour laminage de bandes a basse temperature.
LU87549A1 (fr) * 1988-07-11 1989-10-26 Centre Rech Metallurgique Procede de fabrication d'une bande mince en acier par laminage a chaud

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE788922A (fr) * 1971-09-21 1973-03-15 Uss Eng & Consult Procede pour produire une microstructure a grain ultrafin dans les alliages ferreux
JPS5510648A (en) * 1978-07-10 1980-01-25 Toshiba Corp Memory unit
US4720307A (en) * 1985-05-17 1988-01-19 Nippon Kokan Kabushiki Kaisha Method for producing high strength steel excellent in properties after warm working

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2362658A1 (de) * 1972-12-23 1974-07-18 Nippon Steel Corp Stahlblech mit hervorragender pressverformbarkeit und verfahren zu dessen herstellung
FR2524493A1 (fr) * 1982-04-03 1983-10-07 Nippon Steel Corp Acier ferritique a grains ultra-fins et son procede de production
EP0098564A1 (fr) * 1982-07-09 1984-01-18 MANNESMANN Aktiengesellschaft Procédé de fabrication de tôles soudables à grain fin pour grands tubes
EP0120976A1 (fr) * 1982-10-08 1984-10-10 Kawasaki Steel Corporation Procede de fabrication d'acier lamine a froid pour l'emboutissage profond
EP0196788A2 (fr) * 1985-03-06 1986-10-08 Kawasaki Steel Corporation Procédé de fabrication de tôles d'acier minces laminées, aptes à la mise en forme
BE905966A (fr) * 1986-07-10 1987-06-17 Centre Rech Metallurgique Aciers pour laminage de bandes a basse temperature.
LU87549A1 (fr) * 1988-07-11 1989-10-26 Centre Rech Metallurgique Procede de fabrication d'une bande mince en acier par laminage a chaud

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997026377A1 (fr) * 1996-01-14 1997-07-24 Thyssen Stahl Ag Procede de laminage a chaud de feuillards d'acier
WO1998001589A1 (fr) * 1996-07-08 1998-01-15 Mannesmann Ag Procede de fabrication de tuyaux d'acier sans soudure
WO2000046411A1 (fr) * 1999-02-05 2000-08-10 Centre De Recherches Metallurgiques Asbl Procede de fabrication d'une bande d'acier laminee a chaud pour emboutissage
BE1012462A3 (fr) * 1999-02-05 2000-11-07 Centre Rech Metallurgique Procede de fabrication d'une bande d'acier laminee a chaud pour emboutissage.
WO2006118425A1 (fr) * 2005-05-03 2006-11-09 Posco Feuille d’acier laminee a froid ayant une formabilite superieure et un rapport de rendement eleve et son procede de production
WO2006118423A1 (fr) * 2005-05-03 2006-11-09 Posco Feuille d’acier laminee a froid ayant une formabilite superieure et son procede de production
WO2006118424A1 (fr) * 2005-05-03 2006-11-09 Posco Feuille d’acier laminee a froid ayant un rapport de rendement eleve et moins d’anisotropie et son procede de production
CN101184858B (zh) * 2005-05-03 2010-12-08 Posco公司 具有优良的可成形性的冷轧钢板及其制造方法
WO2008006346A3 (fr) * 2006-07-12 2008-06-26 Univ Kassel Procédé de fabrication d'un demi-produit en tôle adapté pour le formage à chaud

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